Retainer and separator mats for storage batteries



M. ST; G. JENSEN April 27, 1954 RETAINER AND SEPARA'IOR MATS FOR STORAGE BATTERIES Filed Feb. 3, 1949 E 1 a F lf? Ill/ 71722; l luw kl Hun u ISI mmvron. MEEEEI'EH 5:11? JENSEN Q T M ATTYJ! Patented Apr. 27, I954 RETAINER AND SEPARAT OR, MATS FOR STORAGE BATTERIES Meredith St. George Jensen, Toledo, Ohio, assignor to Owens-Corning Fiberglas Corporation, a corporation of Delaware Application February 3, 1949, Serial No. 74,333

10 Claims. (Cl. 136-145) This invention relates to a composite product formed of glass fibers and more particularly to an insulating separator construction especially usable for spacing the plates in a storage battery and to the method of making th product.

In the manufacture of storage batteries it is necessary to space the negative and positive plates by suitable means and insulating means termed separators for this purpose have been made of various materials, as for example, wood and rubber. Rubber is most generally used at present for plate separators in heavy duty batteries but wood is also in use. The'separator is ribbed on the side adjacent the positive plate. This construction permits substantially uninterrupted flow of the electrolyte and facilitates the escape of gas evolved at the positive plates; In use, however, the ribbed separators may fracture or split and permit th lead peroxide or other active material to build up or grow across the space between adjacent plates through the fracture in the separator. This results in decreased effectiveness and eventually in battery failure. The bridging of the space between adjacent-plates by the loosened material is usually referred to as treeing. Also, the ribbed surface of the separators permit the active material to loosen and fall away from the positive plate, and as this progresses, the battery loses its ability to function at rated capacity.

One of the major disadvantages of the various types and character of separator heretofore used is that if the separators are formed so as to snu ly engage the positive plates in a manner to prevent shedding of the active material, the intimate surface contact of the separator decreases the effective action of the electrolyte by impairing the free flow ofelectrolyte into contact with the positive plate. This condition increases the internal resistance of the battery with a consequent corresponding decrease in eiiiciency of the battery.

The present invention embraces the provision of a composite product fabricated of fibrous material which is particularly useful as an insulator or insulating separator for the plates of a storage battery.

An object of the invention i the provision of a composite mat fabricated of fibers, preferably glass fibers or filaments, arranged in a manner suitable for use as an insulator in storage batteries wherein the mat in the region of one surface that engages a battery plate is replete with very small pores foreifectively retaining the active material'on the plates,*the interstices or between adjacent glass filaments or'fibers facilitat ing'the-fiow of electrolyte while retaining the ac- 2 tive material to promote eiiicient operation of a battery.

Another object of the invention resides in th provision of a composite product formed of glass fibers or filaments which may be usable in conjunction with a wood separator or separators of other material or Which may b fashioned in a manner to be self-supporting and usable per se as a battery plate separator.

The further object of the invention resides in the provision of a composite article or unit Wherein a supporting sheet or foundation formed of relatively coarse fibers of glass disposed in random relation is integrated with a suitable binder to impart a semi-rigid character to the sheet and upon which is disposed a quantity of staple sliver providing a high degree of surface resilience by reason of the presence of the staple sliver.

Another object of the invention is the provision of a novel method of joining a group or groups of glass sliver to a base, supporting mat, or web in a manner to facilitate manufacture by a commercially practicable continuous process whereby the composite product may be produced at low cost.

Still another object of the invention resides in the provision of a method of applying a layer or layers'of staple sliver upon a fibrous glass supporting sheet or web utilizing a bonding agent to secure relatively slight adhesion of the sliver to the sheet whereby a desirable degree of resilience in the layer of sliver is obtained.

Another object is the provision of a method of applying groups or strands of glass sliver to a supporting mat in parallel overlapping relation resulting in substantial uniformity in porosity of the product rendering the same particularly adaptable andcommercially practicable as a plate retainer mat or separator for storage batteries.

Another object is the provision of a composite product fabricated of glass fibers particularly usable as a battery retainer mat or insulator, the fibers being arranged and disposed as to facilitate escape of gas evolved at the positive plate as well as to provide a resilient plate-engaging surface serving to minimize the shedding of active material from th plate.

Further objects and advantages are within the scope of this invention, such as relate to the arrangement and function of the related elements of the structure, to various details of construction and method of producing the structure, and to economies of manufacture and numerous other features as willbe apparent from a consideration 3 4 of the specification and drawings of forms of the pp relation The grflllps layers 25 of invention which may b pref red, in hi h: staple sliver are arranged in substantially paral- Figure l a longitudinal sectional i h lel relation. The layer or layers or" sliver are ing a portion of a storage battery embodying a preferably slightly adhered or adhesively joined form of a product of my invention utili d as a to the mat 2 through the use of a suitable binder battery plate tai i means; or bonding agent which may be applied either Figure his a greatly enlarged isomet i View .tothe'layers org-sliver or theifoundation mat 2% illustrating one form of the composite article or at or during the process f l y e liv r on product of my invention particularly illustrating the I have found that gelatin, Starch, p ythe wel'lapping relation of t e o ps or strands -rstyrene, methyl methacrylate, furfural and like of staple sliver arranged onu a supportingsheet; ...materla1s provide a satisfactory bonding agent Figure 3 is an enlarged end view of another for this purpose. The individual filaments of form.of th product illustrating t 1 t1 the staple sliver are preferably formed about position of groups i staple s1iver arranged on eo0023i inch in diameter although other sizes may each uniplanar surface of a "fibrous backing D y fi WilihOllt departing from the SC P O sheet or core; the invention. The sliver is preferably Without Figure l is an end view of=a composite article -3Y- 8129 running about 9 yards or product illustrating another form of the inper pound b ot Sizes a usable- It y be vention; and made-by-any suitable method such as that dis- Figure 5 is a schematic view illustrating steps closed in e cko a d annan Patent N0. in awmethod of -m'y1invent'ion :fOr-iQrming-th 2,264,345,;dated.December..2,-.19.4l.

product -I. have found .in practice thata commercially .Referring to the-drawings indetail and first :usable and acceptable battery insulator .or re- .to Figure '1, I have illustrated a portion of-a :tainer matof this characterzused. in conjunction storage battery having a casing"; of hard rubwith a wood separator-mayebe formed lay-ember, asphaltic compound, .or'othcr'suitable non- -D y wa' O o g fit'z of os '3 conducting vmaterial which enclosesa number 50f fipl t -y c Whifih Partially iof-cells,eaclicomprising-an assembly of'alterv rpp g ple liv rs ar laid, each sliver nately arranged positiveplates l and negative being from A inch 0 /zc in W a v plates 2. Th positiveplatesril of each cell are 8l g adjacent'siivelsibyabout /a 130 0f its joined together andto' a terminal post" i 3, and the Widthnegative plates i2 joined-together and to a ter- W b app ntfrom i ur the sev re-1 minalpost -i4,,the,-latter being connected to the v lapp g slivers-Provide a e o y i ,positiveterminal of an adjacent cell (not shown) brokell'inSlllafing SCTBBHWhiCh When 13130861111111- uby means ofaconnector. er'bar: |5 Each ll i timatecontactwiththe-battery.platesurface has Isealed by means of a suitable asphaltum .cornbeen found very effeC'Bil/ein P e i e S diponnd it. Both positive-and negative-platea ding or" theiactive plate materialsand in other sembliesaresupportedabove-the bottom wall or ys prolonging t life of the yvThe abase of the 'casingitll by afplurality of upwardlylayerof staple sliver .on. the.-base mat 24 provides Textending spaced ribs l1 -.providing a-chamber fla de rceof res e te nglo ho d or retai ..:beneath.the plates for the reception of material the activeimaterial .in the grid 0f 6 8 positive that may becornedislodged-from the plates. plate. Theexceptional fineness ofthe individual ,Disposed between .each .negative and positive laments O fib s making up the layer y plate i r t r gr insulator,constructign is, .of .sliver form a great number of interstices the construction of which forms a part of the 4-5 among 1118 filaments --p minute pores ,present invention. The separatorsserve several through whic t electrolyte y y flow purposes, the t. i o t th ingntomaintain over the entire .areas of .theplates. .Theiproduct the plates in proper spacedrelation-an t i of the present invention provides an efiective preventing the shedding of .active material meansifor maintaining .theactivematerialin the .from the positiveiplates. grids of the positive plates Without impairing the -In. one forinofthe presentinvention thesepaefficiencyrofthe battery or increasingitsinternal rator construction includesa-Wood separator .2! resistance. land between the woodseparatorandthe posi- .As. shown in Figure Lia battery retainer mat .tive plate a retainer matior .unit .22, a .form of construction of theicharacter shown in detail in .the retainermator compositeproductformedof Figure ,zinay be disposed .at both sides of each glass fibers being illustrated .in .Figure2. This ,positive plate, between the plate and the sepa product or article includesa base, mat, backing rator 2i. .sheetor web as fabricated of glass fibers arranged Ordinarilythe space between adjacent positive irregularlyor at random,. the. fibers being bonded and negativep f a t ase battery is from into an integral uniplanar.mass by means of a so .O5.inch.to ,.09 inch. I have found that the mat suitable bonding agent or binder such as poly- .2 3 may be of a thickness or" about .010 inch and styrene resin, starch, gelatin, phenol formaldethe composite sliver and mat construction 22 hyde resin, or furfural resin. The fibers or filaillustrated in Figure. 2 y be, When uncomments of the backing sheet or basez i are usually pressed, about. .020..inch thick and may he inof from .8005 to 46066 inch in diameter, although 5 serted at each side of the positive plate .so that glass fibers of other diameters may be utilizedto the exterior surfaces of the sliver are in 'form the base or'foundationo'f the product made contact with the surfaces of the plates. according to the present invention. The. sheetfi .Myinvention. includes the fabrication ofa com- ;may lie-made in any suitable fashion; for'exaznple, posite mat and sliver construction of a thickness in'the way disclosed in the :Slayter Patent No. so as to be self-supporting. and usable vper se .2,'306,3e7,'dated December122, 1942. as the separator. or insulator between adjacent As shown iniFigure-i2- thereis'supported upon batteryplates. To this end the composite prodthe base 22 a plurality-of groupsgstrands or layers uctmay be. fashioned in the fcrmshownin Fig.- 16 of glass filaments or fibers, herein referred ure 3 whereina mat orcore as is made of greater :to asstaple sliver preferably arranged inoverthickness. than the mat :24 but. manufactured in the same manner of glass fibers disposed in random formation held together by a suitable binder. Upon one or both surfaces of the mat or core 30 there is applied layers 3| of groups of glass filaments or sliver designated 3| arranged in overlapping relation as illustrated in Figure 3 to form a substantially tight unbroken screen ai fording ample porosity to facilitate substantially free flow of electrolyteover the areas of the plates and at the same time prevent or minimize the shedding of active material. The combined thickness of the mat 30 and layers of sliver is such as to snugly occupy the entire space between adjacent positive and negative plates.

In the forms of the product illustrated in Figures 2 and 3, the filaments of the sliver tend to cohere together so that only a relatively small amount of binder or bonding agent serves to cause the filaments disposed immediately adjacent the base or backing sheet to be adhesively joined thereto.

The composite fibrous sheet and sliver oonstruction may, if desired, be made in the form illustrated in Figure 4 in which the glass sliver 34 laid down upon the mat or sheet 35 is of sufiicient width so that one sliver covers the -whole mat. In this form of product, a suitable binder as, for example, gelatin or starch may be used to join the layer of sliver to the sheet 35. A second layer of sliver may be placed on the opposite side of the core 35in producing a separator of the general character shown in Figure 3.

Figure 5 diagrammatically illustrates steps in a method of forming the fibrous mat and sliver construction. In carrying out the method, a supply of prefabricated mat or fibrous sheet 24 is positioned in advance of compression rolls 6i and a supply of staple sliver 26 is supported in a position so that the sliver may be conveyed through the rolls 4! simultaneously with the movement of the mat 24 through the rolls. A suitable binder is sprayed or otherwise deposited upon the mat or upon the groups or strands of sliver before the mat and sliver are brought into contact or engagement through rotation of the rolls ii. A second set of compression rolls 42 is spaced from the rolls 4! to provide a time interval to facilitate the setting or hardening of the binder before the composite or end product 22 is conveyed to a collecting roll 44. In lieu of the specific application of a binder, the base or mat 24, if formed with a thermoplastic bonding agent, such as polystyrene resin, may be heated suificiently to soften the binding agent whereby the sliver may be anchored to the mat 2 3 through the softening and subsequent setting of the binding agent in the mat.

The same principle or method may be used in producing the composite structures shown in Figures 3 and 4, the latter form in addition requiring the application of sliver to the opposite surface of the mat as the mat moves through the compression and conveyor rolls 4 i.

It is to be understood that the figures and dimensions given herein as to the size of glass filaments and the thickness of the backing sheet or web are given by way of example and are not to be taken as limitations of the present invention. a

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

1. An article of manufacture including in combination, a sheet formed of glass fibers wherein the individual fibers are arranged in random re lation, a bonding agent for maintaining the fibers of the sheet in assembled relation, a plurality of layers of unbonded glass sliver supported on said sheet in parallel relation, said layers of sliver being adhesively joined to said sheet.

2. A retainer mat for battery plates including, in combination, a group of glass fibers, means for securing said fibers in integrated condition, a quantity or" unbonded glass sliver disposed on the group of glass fibers with the filaments of the sliver arranged in substantially parallel relation, said sliver being adhesively joined to the group of fibers.

3. An electric storage battery including a plurality of alternately arranged positive and negative plates, insulating means disposed between adjacentplates, said insulating means including a fibrous glass base, a quantity of unbonded staple sliver formed of glass filaments supported on the fibrous base, the filaments of the sliver being disposed in substantially parallel relation, said sliver being arranged in intimate surface engagement with the positive plates.

4. An insulator for battery plates including a supporting web formed of glass fibers bonded together, a layer of glass filaments supported on said web, the filaments of the layer being disposed in substantially parallel relation, said layer being unbonded and compressible in a direction transverse to the normal plane of the web and arranged to resiliently engage substantially the entire surface of a battery plate.

5. A method of forming a fibrous glass structure including the steps of directing a layer of bonded glass fibers and a layer of unbonded glass filaments into juxtaposed surface engagement, of applying a comparatively small amount of adhesive to one of said layers, and of applying a comparatively light pressure to cause only the outermost filaments of the filament layer in contact with the layer of glass fibers to be joined through the mediiun of the adhesive.

6. A method of producing a battery plate retainer including continuously moving a bonded mat of glass fibers, of continuously moving an unbonded sliver of filaments having a high degree of resilience into juxtaposed relation with the bonded mat, of applying a comparatively small amount of adhesive to the mat, and of applying a comparatively light pressure to cause the filaments of the sliver in contact with the mat to adhere to the mat through the medium of the adhesive whereby the high degree of resilience of the sliver is maintained.

7. A composite article of manufacture including, in combination, a foundation mat formed of glass fibers arranged in haphazard relation and bonded together, a layer of unbonded staple sliver of glass fibers arranged in substantially parallel relation on said mat, said layer of glass sliver being adhesively joined to the mat.

8. An article of manufacture including, in combination, a fibrous mat of uniplanar configuration formed of glass fibers arranged in haphazard relation, a bonding agent securing said fibers in integrated mat formation, a plurality of slivers assembled on and secured to the mat, each of said slivers being formed of staple glass fibers arranged in substantially parallel relation, the transverseedge zones of -aeaoh.-.sliver being comparatively thin and in overlappingmelation with the adjacent sliver.

9. A separator for use instorage batteries-inbeing adhesively joined to said mat.

19. An article of manufacture including, in

--combination,a fibrous mat of uniplanar shape formed of glass fibers arranged in haphazard assembled on the mat, each of said slivers being .formed of staple :glass fibers-arrangedin substantially parallel relation, the transverseedge zones of each sliver being comparatively thin and in overlapping relation with .the'adjacent sliver, the fibers of theslivers contacting the .mat being adhesively joined to the mat.

References Cited in the file of'this'patent UNT'TED STATES PATENTS Name Date Ekisler Sept. 17,1935

Number relation, a bonding agent securing said fibers D in integrated mat formation, a plurality of slivers Number Name Date 2,117,371 Slayter May'17, 1 938 2,152,901 Manning Apr. 4, 1939 2,230,271 Simpson Feb. 4,-1941 2,234,560 Keyes Mar. 11, 1941 2,311,704 Simison Feb. 23, 1943 2,454,100 Slayter Nov. 16, 1948 2,477,555 Roberts et a1 July 26, 1949 2,484,787 .Grant Oct. 11, 1949 2,511,887 Vinal June 20, 1950 2,552,124 Tallman ,May 8, 1951 2,574,221 Modigliani Nov. 6, 1951 FOREIGN PATENTS Number Country Date 154,083 'GreatBritain -1 Nov. 25, 1920 832,939 France July 11, 1938 875,272 France Sept. 14, 1942 7 OTHER -REFERENCES Publication--'Philco, Circular Form BID-595, page 2, August 1944. 

2. A RETAINER MAT FOR BATTERY PLATES INCLUDING, IN COMBINATION, A GROUP OF GLASS FIBERS, MEANS FOR SECURING SAID FIBERS IN INTEGRATED CONDITION, A QUANTITY OF GLASS FIBERS SILVER DISPOSED ON THE GROUP OF GLASS FIBERS WITH THE FLAMENTS OF THE SILVER ARRANGED IN SUBSTANTIALLY PARALLEL RELATION, SAID SILVER BEING ADHESIVELY JOINED RELAGROUP OF FIBERS. 